When multiple adaptive bitrate (ABR) streaming clients compete with each other for bandwidth at a bottleneck link the clients may be very unstable, with each client adjusting its requested (and displayed) video rate quite frequently, even when the total bandwidth available to the population as a whole does not change. These frequent shifts in requested/displayed video rate result in a significant degradation in average viewer quality of experience (QoE) for two reasons: (1) the quality level changes are distracting; and (2) the overall quality of experience is biased toward the lowest video rates displayed, since perceptual video quality is, all else being equal, generally a convex function on encoded bitrate.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.